Fatal error: Uncaught Error: Interface 'PDFEmbedder\Viewer\ViewerInterface' not found in /nfs/aesop1/hw00/d50/kenyares/wp-content/plugins/pdf-embedder/src/Viewer/Viewer.php:15 Stack trace: #0 {main} thrown in /nfs/aesop1/hw00/d50/kenyares/wp-content/plugins/pdf-embedder/src/Viewer/Viewer.php on line 15